County (Darilek et al., 2009), where decreasing soil K is, reportedly,one of the top fertility concerns (Sheldrick et al., 2003; Gao et al., 2006) and TK decreased by 9% on agricultural land in Suzhou over an 18 year period (Li et al., 2007). Zhang et al. (2010) reported negative annual K balances on rice/wheat systems, even when K fertilizer application was applied at rates which resulted in a 20% increase of yield.